Particulate product such as roast and ground coffee is conventionally packaged in a vacuum or under pressure. If the roast and ground coffee is packed under pressure, upon initial opening of the container, there is a rush of gas from the interior of the container to the exterior thereof, which rush, if unobstructed, would carry the particulate product with it, thereby causing a mess in the vicinity surrounding the newly opened container. However, if one properly controls the opening structure, this rush of gas can become an advantage by allowing a pleasurable burst of coffee aroma, while restraining the particulate product itself.
Roast and ground coffee is now typically packaged in a cylindrical plated steel can container having a conventional sealed top closure which is openable by puncturing with a can opener or other tool. However, in such closure structures, the size of the opening, the timing of effecting the opening and the gas flow speed are essentially unpredictable, thus allowing no control whatsoever over the flow rate of the initial gas burst and/or retention of the particulate product.
Known conventional plated steel can containers which package roast and ground coffee under pressure generally have some arrangement for controlling the outward flow of the gas burst so as to allow venting of gas while restraining the outward movement of the particulate roast and ground coffee. One such arrangement is shown in the Scholtz U.S. Pat. No. 3,240,383, and another is shown in the Daniel U.S. Pat. No. 5,445,291. Generally, these prior arrangements have the disadvantage of being somewhat complex.
Accordingly, there remains a need for a new and improved container containing particulate product packaged under pressure, which allows for venting of the pressurized gas within the container upon initial opening thereof while substantially retaining the particulate product.